Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, subfamily Pooideae, tribe Poeae
Grass Category
Lawn/Turf Grass, Sports Turf, Golf Course Grass
Variety / Cultivar
Standard commercial blend (e.g., 'Midnight', 'Bewitched')
Hardiness Zones
Thrives in USDA Hardiness Zones 3 through 7; excellent cold tolerance, moderate heat tolerance requiring irrigation in summer transition zones.
About This Grass
Forms a dense, high-quality turf with medium-fine texture and a rich dark green to blue-green color. Mowed height is typically 2 to 2.5 inches, while unmowed it can reach 18 to 24 inches. Produces open, pyramidal panicle seed heads at maturity.
Blade Characteristics
Blades are medium-fine (2-4 mm wide), flat or folded with distinct parallel veins, featuring characteristic boat-shaped tips. Vernation is folded in the bud. Ligule is short and membranous; auricles are absent.
Root System
Moderate to deep fibrous root system with extensive branching rhizomes. Forms a very dense sod, moderate establishment speed, and moderate thatch-forming tendency under high fertility.
Growing Information
Origin Region
Europe, northern Asia, and parts of the mountains of the western US; widely cultivated globally in temperate regions
Growth Habit
Rhizomatous, spreading underground via aggressive horizontal root stalks to form a dense, uniform turf mat
Sunlight & Water Needs
Requires full sun (minimum 6-8 hours daily) with poor shade tolerance. Moderate to high water needs; goes into summer dormancy if severely under-watered. Prefers well-drained, fertile loamy soils with a pH of 6.0-7.0.
Mowing & Maintenance
Mow at 2.0 to 3.0 inches. Requires frequent mowing during peak spring/fall growth. High maintenance level requiring regular fertilization (3-4 lbs N per 1000 sq ft annually), periodic aeration, and dethatching.
Special Characteristics
Exceptional wear tolerance and self-repairing capability due to rhizomes. Good cold tolerance and winter dormancy color loss, fair disease resistance (susceptible to dollar spot and leaf spot under stress).
Ecological Information
Introduced species in North America. Provides soil stabilization and erosion control through dense sod. Commonly blended with Perennial Ryegrass and Fine Fescue.